Rotary clamps are typically used in industrial applications for engaging workpieces of many sizes and shapes during forming and machining operations. Clamp arms may be utilized to secure a workpiece against a workpiece holder or they may be utilized to prohibit movement in a specific direction such as a positive stop. Such rotary clamps typically provide movement of the clamp arms through a pneumatically or hydraulically actuated cylinder which causes the clamp arms to rotate through a desired position and distance. Depending on the specific application, the user may wish to actuate one arm or two arms. The user may wish to have the clamp arms vertically aligned or horizontally aligned, as well as reversible. In addition, all of these specific applications may be utilized in a harsh environmental setting.
In industrial applications, the rotary clamp may be mounted to a support member wherein the mounting arrangement between the support member and the rotary clamp establishes a geometric reference by which all geometric tolerancing, for that application, is based thereon. Thus, all other datums regarding planes, points, tolerances, etc., are measured from this reference. Therefore, the further a particular datum is from the reference or the more intricate and complex the geometric tolerancing of the datum is from the reference, then the more difficult it is to set up the rotary clamp to perform and maintain an accurate and repeatable process. This is especially true when the support member is coupled to a programmable robot wherein the robot moves the rotary clamp between predetermined points along a three-dimensional coordinate system. Thus, it is desirable to have the support member mount to the rotary clamp on the same plane in which the clamp arm mounts to the rotary clamp in order that both the support member and clamp arm share a common reference plane such that no compensation or adjustment of the clamp arm relative to the support member is required.
It is well known in the art to provide a fully sealed, permanently lubricated rotary clamp suited for use in contaminated environments in order to protect the internal mechanisms of the rotary clamp from weld splatter, saw chips, coolants, dust, dirt, etc. Such rotary clamps often have design drawbacks which prevent the support member and clamp arm from being mounted to the rotary clamp on a common plane. For example, relief must be provided between the clamp arm and the rotary clamp's support member mounting surface so that the clamp arm is free to rotate. Also, such sealed rotary clamps are typically time consuming to service and maintenance as they require the rotary clamp to be completely disassembled in order to obtain access to the internal mechanisms of the rotary clamp.